United Kingdom patent application No. 2,071,650, published September 23, 1981, discloses .beta.-lactam antibiotics including (3S)-3-[[(2-amino-4-thiazolyl) [(1-carboxy-1-methylethoxy)imino]acetyl]amino]-2-oxo-1-azetidinesulfonic acid and 4-substituted derivatives thereof.
Escherichia coli acylase has been reported in numerous patents as being useful in preparing 6-aminopenicillanic acid (6-APA) by cleaving the acyl sidechain from Penicillin G under basic conditions as note, for example, U.S. Pat. No. 3,260,653. The use of an immobilized Escherichia coli for this purpose has also been reported as note, for example, U.S. Pat. No. 3,736,230.
Dinelli et al. in British Pat. No. 1,348,359 described employing a bound Escherichia coli to produce semi-synthetic penicillins and cephalosporins from reaction mixtures containing 6-aminopenicillanic acid (6-APA) or 7-amino-cephalosporanic acid (7-ACA) and a suitable carboxylic acid under acidic conditions.